o Charset not defined on mail headers (Content-Type)
o Add too others important Content-Type informations
Merge BSF r 1531:1532 into branch-1_6
And remove duplicate line of BSF!
git-svn-id: http://piwigo.org/svn/branches/branch-1_6@1533 68402e56-0260-453c-a942-63ccdbb3a9ee